Blood Lymphocytes, Thrombocytes

There are undifferentiated stem cells of the blood elements in the bone marrow that differentiate and mature into erythrocytes, (red blood cells), thrombocytes (platelets), and white blood cells (leukocytes and lymphocytes). The production of erythrocytes is regulated by a hormone, erythropoietin (see the section on kidney toxicity), that is synthetized and excreted by the kidney. An increase in the number of premature erythrocytes is an indication of stimulation of erythropoiesis, i.e., increased production of erythrocytes in anemia due to continuous bleeding. 

A complete blood count, or a blood panel, is a medical test to measure the absolute numbers and ratios of different cell types in a given blood sample. In hospital environments, this is one of the most frequently required tests and also recommended as part of regular physical examinations. The test can be applied as a three- or a five-part differential blood count. Both enumerate the erythrocyte (red blood cells, RBCs) and thrombocytes (platelet) content of a whole blood sample. A three part additionally differentiates leukocytes (white blood cells, WBCs) enumerates, while a five-part differential further differentiates the WBCs into lymphocytes, monocytes, neutrophils, basophils, and eosinophils. 

---